Caliper



Patented Feb. 11, 1936 UNITED STATES PATENT OFFICE CALIPER Albert B.Cox, Wilmington, Calif., assignor to Shell Development Company, SanFrancisco, Calif., a corporation of Delaware Application September 28,1929, Serial No. 395,974

9 Claims. (01. 33 -178) My invention relates to those means, usually forindicating'the result of the determination at' termed,ca1ipers, whichare useful for determina distance from the tube.

ing the size of a body. More particularly my in- My invention possessesother advantageous feavention relates to means for determination of thetures some of which with the foregoing will be set extent of a diameterof a body such as a relativeforltlhlzlit letrllgth in Eh; ftfilizwfingdesfcfiption wltiere 5 1y long tub'e. My invention has been particularlyI s a ou ine in u a orm o e mven ion employed in determining theinternal diameter which I have selected for illustration in the drawoftubes used in a tube still in cracking oil and g a c pa y ng and formingpart Of the I shall describe it in this connection. presentspecification. In the drawing I have As is known in the oil refiningart, the oil to be h wn ne form of device emb dying my inv n- 10processed is introduced into a series of relatively tion, but it is g:be understood.1 that I dto not limit long tubes suitably joined togetherto .form myself to sue form, since t e inven ion as se a. tortuousconduit of relatively great length. forth n the Cl y be embedied in theD Throughout a substantial portion of this conduit ty Of Other f ms. g

the'oil is subjected, under considerable pressure, In the d w o W h Iave d efe l5 to relatively intense heat from a furnace. Under ence: gthe working conditions, with the high heat and Fig- 1 1s a schematicView of a device embo ytemperatures on one side of the tube and the mg y{nventwn h p r n pressure of the oil on the other side, together 2 s apl n v w of a ahp s d c 0 with the reacting components contained in thep ye oil, the tubes are subjected to, what is generally t 3 P V thDOTtIOHS f t e c l conceded to be, relatively severe service. In pracp rs d v u way t ll u trat a matter of tice the tubes havea tendency toswell or to be eenetruet'itm- I eroded away at rta points due t erosion,Flg. 4 is an end elevation of the device illuschemical action orforother reasons. It is of t h v f course readily appreciated that, thefailure, under ig. 5 s a sect on along the 0f Fl operating conditions,of a tube with the conse- IS a 'Seetwn along h e quent releasing of thepressure and of the cony l l y be t f fiy f t ii as tained oil into thefurnace is a serious matter. comprising 8 Provision 0 means C lingAccordingly all precautions are usuallyexercised the indication of an gl l t g 30 which are possible to avoid such an occurrence means beingactuated y 0t means a al e and, in this connection, the furnaces areshut to engage the Surfaces f a b y to b ea pe d. down periodically andthe tubes examined. How- I have f nd a I c n suc ss ul cahper t e ever,before an inspector can inspect the tubes inside of a e l s tu e by e poy n ns the furnace and still must be cooled off, otherwise engagingtfihe sulrfacgls oithe tube in colmbiinfiai- 5 the man is subjected tovery disagreeable and i011 Wi eX elna in mg meenS- I1 5 harmfulconditions. Heretofore, also, the inconnection I v sucgessfully employedispector has been compelled to confine his 010- :2 e z i C ib ate? S0tlllgtfillgn a variatilon1 irdl servations substantially to those tubeswhich 8 8 86 r cal circui in w a o u e 40 could be visually inspected fom the outside an indication is given which can be readily interasmuchas there has been no known instrument f' to f h extent of the 511F909with available for calipering the inside diameter of f the calmer 1S mContact In thls P l the tubes throughout their length. In this connon Ihave successfuny employed as an mdlca' nection is to be pointed out thatthe tubes are a e r i i pifi in usually several feet in length, in someinstances a y energlze e i 0 mm t amme-er extending for len ths from 5to 30 feet is conveniently cailbrated so that direct read- It i an t tings can be secured giving the inside diameter or 1 f c my 0 anyvariations therein 01 a tube. To control the v f p cahpenng the msldeindicating means in accordance with the tube ameter of rekfmvely e sizeand with variations therein, I haveemployed P of my f f t the controlmeans indicated generally at l2 which g tg gi 1S Capable gidleatlng at a5- is electrically connected thru conduit l3 to the time e mensiens Of ab Y- indicator. The control means I2 is adapted to A further object ofmy invention is to provide be inserted into a tube and to accommodateitself means for determining the inside of a'tube and to the extent ofthe tube so that a control and 55 variation of the indicator is effectedcorresponding to the dimensions of the tube.

The control means for the indicator has preferably been provided byforming suitable tube engaging means for connection to a handle M whichis useful for inserting the aforementioned means into the tube and forretaining it in a predtermined position relative to the tube. The handleis conveniently joined to a hollow member I6 as by welding. The memberI6 is conveniently provided with an aperture II to receive the conduitl3 and to permit its insertion and passage thru the handle.

To secure the tube engaging means I preferably position spider 2|between the member l6 and extension member 22. Conveniently theextension member is adapted to be screwed into the hollow member I; bythreads 23 so that the spider is positively secured in position. Asecond spider 26 is conveniently secured at the other end of theextension member 22 by threadedly securing a member 21 having a boss 28to the extension.

Means are provided upon each of these spiders for engaging the tube.Thus, I provide arouately formed arms 29 pivotally mounted upon eachspider arm 3| by pins 32. I preferably provide a plurality of the armsupon each of the spider arms and adjacent each other so that a roller 33is conveniently rotatably mounted between them. To ensure that the armsare maintained apart a sufficient distance so that an easy turning ofthe rollers is possible, I provide spacers 34 which are secured betweenthe respective arms by bolts 36. I

For reasons which will presently appear '1 form extensions 4| on each ofthe arms 29 in such a manner that the extensions are adapted to beabutted by sliding members 42 carried on the extending member 22.rollers 33 with the surface of the tube the extensions 41 will be movedwith respect to the spider arms 3| so that the sliding members 42 areslid along the extension 22. To urge the rollers 33 into engagement withthe surfaces of the tubes I preferably position a. spring 43 between thesliding members 42 and about the extension 22 so that the slidingmembers are biased and are urged apart. It is believed to be apparentthat, in this manner, the several tube contacting means are constantlyurged into full and close engagement with the surfaces of the tube.

In conjunction with the tube contacting means I preferably providemeansfor controlling the indicator l I in accordance with variationsoccurring in the contacting means. Preferably, I accomplish this bycontinuing arms 29 to form ends 5|. of the opposite arms so that aswelling of the tube along substantially only one diameter is indicated.It is of course apparent that modifications may be readily made toenableindications to be secured simultaneously along another or severaldiameters of the tube. I will term the arms 29 having the ends 5| asfeelers to distinguish them from the arms 29 without the end additionwhich latter I will term guides.

Pivotally joined to each of the ends 5| are fingers 52. A shaft 53,which is carried by the hollow extension 21, has a yoke 54 formed at oneend. This yoke is adapted to receive the fingers 52 and to be movablyjoined to them by pins 56.

The shaft 53 preferably extends thru into a channel 51 formed in themember 22. A usually Upon a contacting of the This has preferably beendone with only two' 53 and carries a spring 59. The spring is providedto abut against the member 21 while a nut 6| provided on the end of theshaft, serves to adjust the tension of the spring. Upon a movement ofthe ends of the feelers to which the fingers are joined the fingersretractably urge the shaft into or out of the member 21. The fingers areso arranged that this movement corresponds substantially with themovement of the feelers. However, I prefer that the relationship of thefingers to the feelers be such that a considerable magnification iseffected of the movement of the rollers'when this movement istransmitted by the fingers to the shaft 53.

I preferably utilize the movement of the shaft 53 to furnish a controlfor the exteriorly provided indicating means. This I have effected byforming a rack H along the shaft and by providing a gear 12 rotatablywithin the member 21 so that it contacts with the rack and is rotatedupon movement thereof. A stub shaft 13 extends thru the member 21 and isrotatable therein to carry the gear 12. This shaft I utilize to vary theposition of a contact arm (not shown) provided on the shaft with respectto a resistance element 16 formed on a base 14. The resistance 18 andthe rotatable contacting.arms are provided in the circuit of theindicating means, so that a suitable variation is made of the resistancein the circuit in accordance with the movement of the tube engagingmeans.

With the indicating means suitably calibrated the calipering device issuitably inserted for calipering into a tube 8|. Preferably thecalipering means is introduced by means of a tube 82 which conformssubstantially to the dimensions of the tube to be calipered. Thismaterially facilitates the introduction of the calipering means. Uponacontacting of the caliper ng means with a swelling in the tubes as isindicated at 83 in Fig. 1 the feelers will be urged out into contactingwith the swelling surfaces and will, accordingly, as I have previouslyset forth, vary the circuit controlling means. This variation will beindicated on the indicating means. In accordance with the calibration ofthe indicating means the extent of the variation and of the swelling inthe tube can be determined. The flexible handle I 4 is preferably ofsuch a length that the calipering device can be extended into the tubeand manipulated throughout its length.

-I claim:

1.'In a calipering device for detecting and measuring variations in theinside diameter of a relatively long cylindrical tube, the combinationof an elongated member adapted for longitudinal movement within thetube, spring-expanded bell crank-shaped feelers mounted at one end andspring expanded guides mounted at both ends of the said member forcontinuously centering same in the tube, contact rollers mounted on thefeelers at a distance from the outer ends thereof, link connectionsbetween said ends of the feelers allowing radial expansion thereof, andan indicating means cooperating with said link connections for measuringthe radial movement of the feelers.

2. In a calipering device for detecting and measuring variations in theinside diameter of a relatively long cylindrical tube, a combination ofan elongated member adapted for longitudinal movement within the tube,spring-expanded bell crank-shaped feelers mounted at one end and springexpanded guides mounted at both ends of respectto the pair of opposedguide'arms, and

said member for continuously centering same in the tube, contact rollersmounted on the feelers at a distance from the outer end thereof, linkconnections between said ends of the feelers allowing radial expansionthereof, a spring means operating to maintain said link connectionsunder tension, and an indicating means cooperating with said linkconnections for measuring the radial movement 'of the feelers.

3. In a calipering device of the type described, an elongated member, apair of opposed radially expansible guide arms mounted on said memberand adapted to engage the inner walls of the tube, resilient meansurging said opposed members against the inner wall of said tube, a pairof radially opposed feelers on said member circumferentially staggeredwith respect to the guide members and adapted to engage the inner wallof said tube, said resilient means also being connected to said feelersfor pressing same against said wall, and means for indicating the radialmovement of said feelers.

4. A calipering device comprising a hollow elongated member, means onsaid member to center it in a tube, a plunger slidably mounted in saidmember, resilient means arranged to urge said plunger in one direction,at least one feeler arm pivoted on said member and adapted to engage theinner wall of the tube by outward angular movement of said feeler armabout its pivot, a link pivotally connected to said feeler and to saidplu ger and arranged to move the plunger in opposition to the action ofsaid resilient means when the feeler is moved inwardly, said linkscontinuously translating the tension of the resilient means to thefeelers to press them against the walls of the tube and means toindicate the movement of said plunger.

5. A calipering device comprising an elongated member, means on saidmember to center it in a tube, an axial recess in said member, anaxially movable plunger in said recess, spring means arranged to urgesaid plunger in one direction, a plurality of feeler arms pivoted onsaid member and adapted to engagethe inner walls of said tube by outwardangular movement of said feeler arms about their pivots, a link for eachfeeler arm pivotally connected to its feeler arm and to said plungerandarranged to move the plunger in opposition to the action of saidspring means when its feeler arm is moved inwardly, said linkscontinuously translating the tension of the spring means to the feelersto press them against the walls of the tube, and means to in dicate themovement of said plunger.

6. A calipering device comprising an elongated member, means at a firstend of said member to center said end in a tube being calipered, a pairof radially opposed guide arms at the second end of said member arrangedto center the latter end of said member in the tube, an axial recess insaid member, an axially movable plunger in said recess, spring meansarranged to urge said plunger in one direction, a pair of radiallyopposed feeler arms pivoted on said member at its second end,circumferentially staggered with adapted to engage the inner walls ofsaid tube by outward angular movement of said feeler arms about theirpivots, a link for each feeler arm pivotally connected to its feeler armand to said plunger arm arranged to move the plunger in opposition tothe action of said spring means when its feeler arm is moved inwardly,said links continuously translating the tension of the spring means tothe feelers to press them against the walls of the tube, and means toindicate the movement of said plunger. I

7. In a calipering device having an elongated member, radially movablefeeler means on said member and means to indicate the radial movement ofsaid feeler means, the combination of a plurality of circumferentiallyspaced guide arms pivotally mounted at each end of said member adaptedto engage the inner wall of a tube and to center the said member in saidtube, a collar at .each end of said member arranged and constructed tomove the guide arms at its end outwardly by engagement with said guidearms, and common spring means on said member arranged to press both saidcollars into engagement with the guide'arms, whereby the force of saidspring will move the guide arms outwardly.

8. In a calipering device for detecting and measuring variations in theinside diameter of a relatively long cylindrical tube, the combinationof an elongated member adapted for longitudinal movement within thetube, spring-expanded feelers mounted at one end and spring expandedguides pivotally mounted at both ends of said member for continuouslycentering the same in the tube, a slidable plunger axially mountedwithin said member, link connections between said plunger and theoutward ends of the feelers adapted to move the plunger axially in onedirection when the feelers move outwardly, and to move the plunger inthe opposite direction when the feelers move inwardly, and indicatingmeans cooperating with said plunger and said link connections formeasuring the radial movement of the feelers.

9. In a calipering device for detecting and measuring variations in theinside diameter 0! a relatively long cylindrical tube, the combinationof an elongated member adapted for longitudinal movement within thetube, spring-expanded feelers mounted at one end and spring expandedguides pivotally mounted at both ends of said member for continuouslycentering the same in the tube, a slidable plunger provided with a rackmounted within said member, link connections between said plunger andthe outward ends of the feelers adapted to move the plunger axially inone direction when the feelers move outwardly, and to move the plungerin the opposite direction when the feelers move inwardly, a pinionmounted Within said member and engaging said rack, and indicating meanscooperating with said pinion to register the amount of axial movement ofthe rack caused by radial expansion of the feelers.

ALBERT B. COX.

